Washer box for treating coal or other granular substance



March 31,1936.

WASHER BOX FOR TREATING COAL OR OTHER GRANULAR SUBSTANCES Filed Oct. 22, 1934 2 Sheets-Shet 1 INVE/V 1' A. A. HIRST 2,035Q750 March 31, 1936. AAEHRST 2,035,750

WASHFR BOX FOR TREATING COAL OR OTHER GRANULAR SUBSTANCES Filed Opt. 22,;934 2 sheets-Shea 2 ArH'uurNge non HOP?! INVENT Q Patented Mar. 31, 1936 sr'rss WASHER BOX FOR TREATING COAL OR OTHER GRANULAR SUBSTANCE Arthur Algernon Hirst, Birmingham, England 12 Claims. (Cl. 209-455) (Granted under the provisions of sec. 14, act of March 2, 1927; 357 0. G. 5)

This invention relates to washer boxes for coal and the like and. of the kind in which the material to be washed is caused to travel over perforated plating through which a pulsating current of water is caused to flow, and particularly to washer boxes in which the pulsations of the water are produced by the action of air uncler pressure, though the invention is applicable in cases where the pulsations are produced by any equivalent means such as, for instance, a mechanically operated plunger. The invention is concerned with the type of washer box in which the heavy material which collects on the perforated plating is discharged partly through an outlet gate or gates and partly (in the case of the fine heavy material) through the perforated plating.

In such washer boxes it is desirable that the strength of the pulsations should be adjusted in accordance with the rate of feed of material to the washer box, that is, the throughput, and further, in accordance with the size and density of material being treated.

The object of the invention is to provide means enabling such adjustment so that washer boxes can be arranged to deal with feed of material coming direct from colliery screens and the pulsations are automatically adjusted according to the throughput, sizing, size, distribution and density of the material fed to the box.

The invention provides a washer box of the kind referred to including a float suspended in the working bed of the box and means connected to or associated with said float for controlling the strength of the pulsations, the arrangement being that when the working bed becomes too tight or insuiflciently fluid the strength of the pulsations is increased and when the bed is too loose or too fluid the pulsations are correspondingly weakened.

I have found that a float suspended in the working bed of a washer box, generally speaking, tends to rise when the pulsations are too weak and to fall when the pulsations are too strong.

If the size, density or quantity of material fed into the box becomes greater than can be dealt with by the pulsations, there is a tendency for the bed to become tightened and less fluid and unless the pulsations are strengthened there is a tendency for the tightening of the bed to cause a further weakening of the pulsations.

The tightening of the bed, however, in a box according to the present invention causes the float to rise and this movement can be utilized to strengthen the pulsations in accordance with the increase in size, density or quantity of material being fed,

If the size, density or quantity of the material fed into the box is reduced without corresponding' decrease in the strength of the pulsations, the operation of the washer box is impaired, since the pulsations are then too strong for eflicient stratification.

With a box according to the present invention reduction in the .density, size or quantity of the material being fed through the box causes the working bed to become loose or more fluid and the float tends to fall, this movement being utilized to reduce the strength of the pulsations in proportion to the alteration in the quantity or quality of the material being treated.

The float preferably projects above the material and water contained in the box so that there is no danger of the float becoming buried in the bed and the operation being interfered with by accumulations of material on top of the float and in addition the float is preferably tapered or rounded towards its lower part so that the bed can more readily move the float as the fluidity increases or decreases.

It is not necessary in every case to provide continuous automatic regulations of the strength of the pulsations applied to the Washer box, and for example, the apparatus may be arranged so that any one out three or four diiierent strengths of pulsations can be applied to the box, the movement of the float being utilized to select the most suitable value for the particular conditions of the working bed.

The float may control the movement of a cam by means of which the blo -ofi valves for the air supply or air vessel are regulated or controlled to the desired extent.

Referring to the drawings:-

Figure 1 is a transverse elevational view partly in section of a portion of a washer box and controlling apparatus according to the present invention.

Figure 2 is a longitudinal elevational view of same.

Figure 3 shows, to an enlarged'scale, a part of the controlling apparatus illustrated in Figure 1.

Figure 4 is a side elevation of same.

Figure. 5 is a view partly in section of a modified form of controlling apparatus.

In the construction illustrated in Figures 1 to 3 the invention is applied to a washer box of the well known type in which the pulsations are produced by the action of air under pressure, this air being periodically admitted above the surface of'the water in a closed portion of the box and the air pressure being relieved between the periods of admission so that the water level in the closed portion of the box is periodically depressed and allowed to return to the normal level, thus producing in the box itself and the working bed a pulsation of water which performs the stratification of the material to be treated. p

In this construction the Washer box 4 is provided at one end with an inlet feed chute 5 and is divided by means of a vertical partition 6, the box having a perforated base 1 through which the pulsations act upon the material to be treated in the box.

The dirt or heavy material collecting on the portion of the perforated base on the inlet side of the partition 6 is discharged through a conduit 8 and star valve or discharge member 9.

When the material enters the box from the chute 5 it is stratifled by the pulsations and the" lighter material, such for example, as the washed coal is moved over the partition 6 into a further compartment of the washer box whilst the heavier material or dirt falls to the perforated base plating I.

Some of the finer particles pass through the holesin' the plating whilst the remainder ofthe heavy material is removed through the conduit 8', the mouth of which can be partially covered by an adjustable gate lb.

As is well known the box is of U shape in transverse section, being divided by the wall 44 into two compartments, a washing compartment 4, part of which is shown in Figure 2, and an air pressure compartment 3' behind the wall 44, the water being normally at the same level in both compartments. I

Compressed air is applied above the level of the water in the air pressure compartment 3 and this level is thereby depressed, the water being forced into the washing compartment 4 and passing' through the base plating l in an upward current.

When the airpressure is relieved thewater returns to its normal level and the pulsations thus produced in the washing compartment stratify the material. f

The supply of compressed air from a main 2 is controlled in the known manner by means of slidable valves mounted in valve casings l l, the valves themselves being moved by means of connecting rods 12 linke'd'between the valve rods i3 and eccentrics M or other operating mechanism.

Within the first portion of the washer box a float I5 is suspended upon a rod i6 guided by the pairs of rollers 45 secured to a suitable superstructure and the float is normally located in the box with the inverted conical part I! immersed in the working bed.

The float projects above the material and the water in the box and whilst the upper portion I8 is illustrated as oiv conical form to prevent accumulation of material on top of the float this is not essential and the float may have a rounded or even flat top.

To the upper end of'the rod I6 is attached a roller chain l9 which passes over a chain sprocket 20 and which carries at its free end a counter-poise weight 2|.

The sprocket 20 is mounted upon a spindle 22 carried by brackets 23 on the super-structure and to the spindle 22 are attached four cams 24a, 24b,

240 and 24d, each having a depressed peripheral portion 25 terminating at one end in an inclined step. On each of the first three cams 24a, 24b and 240 the inclined step is at the left hand end of the depressed portion 25 as seen in Figure 2 and these three steps are arranged in succession as shown at 25a, 25b and 250 in Figure 2, whilst; at its right hand end as seen in that figure each depressed portion 25, terminates in a square; shoulder 25c at the position shown in Figure 2.

On the fourth cam 24d the inclined shoulder is arranged at 25d at the right hand end of the portion 35 and at its opposite end the portion 25 ends in a square shoulder 25 Each cam is fixed on the spindle by means of clamping nuts and the cams are individually ad.- justable on the spindle.

For each cam a control valve, of the form shown in Figure 2 is provided and the valve comprises .a box 26 having a transverse partition 21 above which connects a pipe 28' communicating with the air line whilst a further pipe 29 communicates with the boX' below the partition 21.

A valve spindle 3B slidably mounted in guides in the box carries at its lower end a roller 3|" engaging the peripheral edge of its associated cam, whilst two poppet valves 32 and 33 are secured at space-d positions to the valve spindle, the valve 33 engaging a seat in the partition 21 whilst the valve 32 is engageable with a seat 341 in one end of the box.

The control valves for the cams 24a, 24b and 240 each operates a relay associated with a blow-off valvein the pipe line, or on the air vesseland the pipe 29 from each of these control valves passes to a relay as shown in Figure 1.

Each relay comprises a casing 35 in which is mounted a slidabl'e piston rod 36 carrying a piston 37 and the casing is formed as a cylinder for the piston 31 which may be'provided with the usual sealing rings or washers.

The casing 35' is secured in position so that the. lower end of the piston rod 36 is immediately above the spindle 38 of a blow-ofi valve 39 mounted on the end of a pipe 40 communicating with the air line.

The valve 39 is loaded with suitable weights 4!. so that it blows-off at a definite pressure and relieves the air pressure in the line and in the normal position of the relay as shown in Figure 1, the operation of the blow-ofi valve is unaffected by the relay. The piston 3'1 is retained in the position shown by means of a spring 42 and the low end of the piston rod is clear of the upper end of the valve rod 38.

With the relay in this position the control valve associated with this relay is in the position shown in Figure 2 and the valve 33 is en gaging its seating as shown in Figure 2 so that communication between the pipe 28 and 29 is cut ofi.

When the cam 24 is rotated in a clockwise direction from the position in Figure 2 so that the step of 25a engages the roller 3i and .due to an upward movement of the float, the valve rod 30 is moved upwards in the box 26 and the valve 33 is opened 50 that the air pressure from the pipe 28 is communicated to the pipe 29.

Pressure is accordingly applied above the piston 31 and this is depressed so that the end of the piston rod 36 engages the end of the valve rod 38 and prevents the valve 39 blowing off.

When the washer box is operating normally the weights on the blow-01f valves and the position of the cams on the spindle are arranged by trial so that the resulting air pressure is such that suitable pulsations are produced in the washer box to clean the normal supply of coal satisfactorily.

- I give below by way of an example operating pressures for the various control valves, but it will be understood that these pressures given are not in any way limited and may be varied in accordance with requirements for any particular size or grade of material being treated.

In this example, the control valve operated by the cam 24a may be connected by the pipe 29 to a relay mounted above a blow-off valve loaded to a pressure of one and a half pounds per square inch, so that if the blow-off valve is not held down by the relay piston it blows off when a pressure of one and a half pounds per square inch is built up in the air supply pipe and by this means the pressure applied to the washer box is limited to one and a half pounds per square inch.

The control valve associated with the cam 24b is similarly connected to a further relay disposed above a second blow-ofi valve loaded to the pressure of two pounds per square inch, whilst for the third cam 240 there is provided a further blow-off valve loaded to the pressure of two and a half pounds per square inch.

The washer box operates normally at a pressure of two pounds per square inch and for normal quantities and sizes of material this air pressure produces pulsations of the necessary strength for stratifying the material.

To apply this pressure to the washer box the float and the cams are arranged so that with normal operation the valve 24a is rotated from the position shown in Figure 2 until the inclined step a engages the roller 3| and moves the spindle to close the poppet valve 32 on to its seat 34 and remove the valve 33 from its seat in the partition 21.

Thus communication is established between the pipe 28 and the pipe 29 and air pressure from the supply line is communicated through the pipe 29 tothe relay associated with the blow-off valve loaded to one and a half pounds per square inch. The pressure thus applied above the piston of the relay depresses it against the action of the spring 42 until the lower end of the piston rod 36 engages the upper end of the-spindle of the blow-off valve which is thus prevented from rising or blowing off.

Consequently the pressure in the air supply line can be built up until it reaches two pounds per square inch, but the pressure cannot exceed this figure as the second blow-oh" valve then comes into operation and maintains the pressure in the supply line at two pounds per square inch.

The box normally operates with the cam 24a in this position, but with the rollers associated with the remaining three cams disposed in the depressions 25 and with the steps 25b and 25c out of engagement with the rollers.

If the quantity of material entering the box increases above the normal or material of greater size or density is fed into the box, there would be a tendency for the working bed to become more tight or less fluid and if the pulsations were retained at the normal strength the operation of the box would be impaired.

The less fluid bed however causes the float l5 to rise and this action is assisted by the shape of the float, since a relatively tight bed tends to squeeze the portion l! of the float upwardly.

. This upward movement of the float rotates the V cam spindle and the inclinedstep 25b on the cam .241) is moved under the roller of the control valve associated with this cam.

This movement operates the control valve as described above with reference to the cam 24a and the air pressure is applied to the relay associated with the second blow-oil valve operating at a pressure of two pounds per square inch and this second blow-off valve is also prevented from operating so thatthe pressure is again built up in the air line.

The pressure is now increaseduntil the third blow-off .valve operates at a. pressure of two and a half pounds per square inch and the strength of the pulsations is consequently increased to accommodate the alteration in the density of the bed consequent on the alteration of the material entering the box.

Reverting now to the normal condition of the bed with only the first blow-01f valve closed and the box operating at a pressure of two pounds per square inch, if the quantity, size or density of the material being fed into the box decreases the bed becomes more loose and fluid and the float falls, this movement of the float being again assisted by the inverted conical portion I! which penetrates a relatively loose bed.

The downward movement of the float rotates the cam spindle in the opposite direction to that described above and the step 25a is movedfrom beneath this roller and theparts take up the position shown in Figure 2 with the roller in the depressed portion 25.

The communication between the pipes 28 and 29 is cut off by the valve 33 and the pipe 24 is connected to atmosphere when the valve 32 leaves its seat 34 so that the spring 42 moves the relay piston to the position shown in'Figure l and consequently frees the blow-off valve.

This blow-off valve then operates and reduces the pressure down to one and a half pounds per square inch and the strength of the pulsations applied to the washer box are consequently decreased to accommodate the alteration in the material fed to the box.

A tap 43 is provided in the pipe 29 and is ad justed so that air enters or is released from the relays relatively slowly so that the air pressure is not changed suddenly in a manner which would unduly stress the air compressor and its driving mechanism.

The pulsations produced by a pressure of two and a half pounds are suitable for accommodating overloading or feeds mostly of cobble or coal of relatively large size, whilst the pulsations produced by the pressure of one and a half pounds are suitable for underloading or feeds mostly of fines or relatively small coal.

The cam 24d takes charge of conditions when the supply of material to the box ceases entirely or nearly so and the pipe 29 from the control valve associated with this cam is'connected to an air blower 59, such as a whistle, horn or the like, the operation of which will indicate to the operator in charge of the washer box that abnormal conditions are prevailing.

When the supply of material either ceases or falls considerably below the quantity for normal operation, the bed becomes very loose and the float falls below the position in which the relay associated with the one and a half pounds blowoff valve is operated and this downward movement of the float rotates the cams in an anti-clockwise direction from the position shown in Figure 2.

The inclined step 25d on the cam 24d is thus.

brought into engagement with its associated roller 'and the poppet valve 32 of this relay is moved on to its seat 34, whilst the valve 33 of the relay is moved ofi its seat in the partition 21.

The air pressure is thus applied to the alarm whistle or horn through the pipes 28 and 29 and an indication is given to the operator.

The alarm device may, if desired, comprise a bell, the signal, lamp or other visible signalling device being operated by air pressure applied through the pipe 29.

i It would be necessary for the operator to make further adjustments to the apparatus inthe event of complete failure of the supply to the box so that an alarm device to indicate failure of the supply is in most cases adequate.

- Suitable stops 46 are provided on the float rod I6 to limit the possible movements of the float and prevent the latter falling to the bottom of the box or on to the base plating I when the apparatus is standing by or being cleaned or adjusted.

The above construction is suitable for the control of apparatus in which the supply of compressed air is supplied by a positive blower, but when the invention is applied to apparatus where the supply of air is provided by a centrifugal or turbo-blower the control may be provided at the inlet to the blower instead of, or in addition to, governing the pressure at which the air supply is allowed to blow off through valves as described above.

A suitable construction for the control in such cases is'illustrated in Figure 4 and in this construction the pipe 41 represents a portion of the inlet pipe to the blower 58, the volume of air passing to the latter being controlled by means of an adjustable valve 48. a

The valve is mounted upon a spindle to which is attached a sprocket wheel 49 over which passes 'a chain 58 connected at one end to a piston 5| in a relay cylinder 52 and having at its other end a balance weight 53.

The initial position of the valve 48 for normal operation of the apparatus is governed by means of weights 54 placed upon 'the'piston to balance the-effect of the weight 53 and the piston abuts against the end ofa stop spindle 55 which is externally screw threaded and engages in a screw threaded hole in the lower'end disc of the relay cylinder 52.

A- pipe 56communicates-with'a branch passage leading to the interior ofthe relay cylinder below the piston 5| and this'pipe '55 is connected to the pipe29 of one of the control valvesdescribed-above in cooperationwith the cams-24.

When the control valve is operated as previously described the air pressure from the pipe 2 8 is quently increase the strength of the pulsations.

As shown in Figure '4 the valve 48 is in the position for lowpressure pulsations and the valve is opened from'this position-by the cam "24a and is opened further when the float rises sufficiently to close the control valve associated with the cam 24b.

'The precise value of the operating pressures obtained with the various movements of the butterfly valve can be adjusted by means of the sprocket wheel 49 or by adjusting the stop 55 by means of the handle 51. I

"The weights 53 and 54 are arranged so'that when thezpipe 56 is connected to atmosphere through the control valves, the weight 54 returns the piston 5l'to the position shown in the figure and for other pressures the weight 53 and the effect of the air pressure beneath the piston are balanced by the weight 54 in the new position of the butterfly valve.

The relay cylinder is provided with stops 58 to limit the upward movement of the .piston. I have-described the invention :as controlling or regulating the main air supply to the washer box, but where the box is divided into a plurality of compartments as is common with washer boxes of this type, .a plurality of. floats asdescribed above :may beprovidedto control the strengths of the pulsations applied to the individual compartments of the Washer box so that pulsations are applied to each compartmentin direct proportion to the requirements of that compartment and'irrespective of the remaining compartments of the box.

The construction described and illustrated-provides for four working pressures in addition to the alarm signal or whistle, namely pressures of one and a half pounds per square inch, two

pounds per "square inch, two and ahalf pounds per square inch and .over two and a half pounds per square inch..

If; however, only three working pressures are required in addition to the alarm whistle orsignal the cam -24cand its associated control valve may be-omitted.

What I claim then is:

1. A washer box for coal and the like including a washing compartment, a closed air pressure compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with water to a'common level, means for admitting air under pressure intermittently to said air compartment above the level of the water therein :to depress said level, said air being released 'be- "tween'such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating in said washing compartment, the material to be washed being adapted'to form a working bed on said plating, a float adapted to be suspended in said working bed, said float being mounted for rising and falling movement'in said bed, air admission means for controlling the admission of air to said air compartment, said means being operated automatically from said float in proportion to the movements of the float in the working'bed to control the strength of'the pulsationsin the water in the r washing compartment.

2. A washer'box for coal and the likeincluding a washing compartment, a closed air pressure compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with water to a common level, means for admitting air under pressure intermittently to said air compartment above the level of the water therein to depress said level, said air being released between such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating in said washing compartment, the material to be washed being adapted to form a working bed on said plating, a float adapted to be suspended in said working bed, said float being mounted for rising and falling movement in said bed, air admission means for controlling the pressure of air admitted to said compartment, and means associated with said float for controlling the operation of said air admission means to regulate the admission of air in proportion to the movements of the float in the working bed.

3. A washer box for coal and the like including a washing compartment, a closed air pressure compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with water to a common level, a compressed air supply source, means for admitting air under pressure intermittently to said air compartment above the level of the water therein to depress said level, said air being released between such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating in said washing compartment, the material to be Washed being adapted to form a working bed on said plating, a float adapted to be suspended in said working bed, said float being mounted for rising and falling movement insaid bed, and means for controlling the pressure of air admitted to said compartment in proportion to the movements of the float in the working bed to control the strength of the pulsations in the water in the washing compartment, said means including a blow-off valve in the compressed air supply, relay mechanism for controlling the operation of said blow-off valve, and means associated with said float for operating said relay mechanism.

4. A washer box for coal and the like including a washing compartment, a closed air pressure compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with Water to a common level, a compressed air supply source, means for admitting air under pressure intermittently to said air compartment above the level of the water therein to depress said level, said air being released between such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating in said washing compartment,'the material to be washed being adapted to form a working bed on said plating, a float adapted to be suspended in said working bed, said float being mounted for rising and falling movement in said bed, and means for controlling the pressure of air admitted to said compartment in proportion to the movements of the float in the working bed to control the strength of the pulsations in the water in the washing compartment, said means including a plurality of blow-ofi valves in said compressed air supply, said blow-ofi valves being loaded to operate at difierent pressures, relay mechanism for controlling the operation of said blow-ofi valves, and means associated with said float for operating said relay mechanism selectively to control the operation of said blow-ofi valves.

5. A washer box for coal and the like including a Washing compartment, a closed air pressure compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with water to a common level, a compressed air supply source, means for admitting air under pressure intermittently to said air compartment above the level of the water therein to depress said level, said air being released between Such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating in said washing compartment, the material to be washed being adapted to form a Working bed on said plating. a float adapted to be suspended in above the level of the water 5 said worldng bed, said float being mounted for rising and falling movement in said bed, and means for controlling the pressure of air admitted to said compartment in proportion to the movements of the float in the working bed to control the strength of the pulsations in the water in the washing compartment, said means including a plurality of blow-oil valves in said compressed air supply, said blowofi valves being loaded to operate at diiferent pressures, relay mechanism for controlling the operation of said blow-ofivalves, control valves for operating said relay mechanism selectively to control the operation of said blow-off valves, and means associated with said floatfor operating said control valves.

' 6. A washer box for coal and. the like including a washing compartment, a closed air pressure "compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with water to a common level, a compressed air supply source, means for admitting air under pressure intermittently to said air compartment therein to depress said level, said air beingreleased between such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating in said washing compartment, the material to be washed being adapted to form a working bed on said plating, a float adapted to besuspended in said working bed, said float being mounted for rising and falling movement insaid bed, a plurality of blow-ofi valves in said compressed air supply, said blow-ofi valvesbeing loaded to operate at different pressures, relay mechanism for controlling the operation of said blow-oiT valves, control valves for operating said relay mechanism selectively to control the operation of said blow-off valves, and cam mechanism for operating .said control valves, said cam mechanism being operatively connected to said float for operation in relation to the movements of the float in the working bed.

7. A washer box for coal and the like including a washing compartment, a closed air pressure compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with water to a common level, a compressed air supply source, means for admitting air under pressure intermittently to said air compartment above the level of the water therein to depress said level, said air being released between such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating-in said washing compartment,

the material to be washed being adapted to form a working'bed on said plating, a float adapted to be suspended in said working bed, said float being mounted for rising and falling movement in said bed, a plurality of blow-off valves in said compressed air supply, said blow-ofi' valves being loaded to operate at diiTerent pressures, a relay device for each of said blow-ofl valves for con trolling the operation thereof, a control valve for each of said relay devices, said control valve in one position being adapted to connect the relay device to said air supply source and in another position to cut off the said connection, cam mechanism for operating said control valves, said cam mechanismbeing operatively connected to said float and. being adapted to operate said control valves selectively to control the operation of co'mpartment communicating at its lower said blow-off valves in'proportion to the movements of the float in the working bed.

8. A washer box for coal and the like including a washing compartment, a closed air pressure compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with water to a common level, a compressed air supply source, means-for admitting air under pressure intermittently to said air compartment above the level of the water therein to depress said level, said air being released between such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating in said washing compartment, the material to be ,washed being adapted to form a working bed on said plating, a float adapted to be suspended in said working bed, said float being mounted for rising and falling movement in said bed, a plurality of blow-off valves in said compressed air supply, said blow-off valves being loaded to operate-at different pressures, a relay device for each of said blow-off valves for controlling the operation thereof, a-con-trol valve forea-ch of said relay devices, said control valve in one position being'adapted to connect the relay device to said -,air supply source and in another position to cut off the said connection, a cam for operating each control valve, a spindle to which said cams are connected, a sprocket" wheel mountedon said spindle, a chain engaging said; sprocket and con- :nected to said float, so that movements of the float in said working bed operates said control valves selectively to control the operation of said blow-on valves. r

.9. A washer'box for coal and the like including a washing compartment, a closed air :pressure compartment communicating at itslower part with said washing compartment, bothbf said compartments being adapted to be filled with water to a common level, an air compressor, sup- ,ply pipes from said compressor to said air compartment, means for, admitting air under pressure intermittently to said air compartment abovethe level of the water therein to depress said level, said air being released between such admissions to produce aupulsating current of water in said washing compartment, a periorated base'plating in said washing compartment, the material to be washed being adapted to form a working bed on said plating, a float adapted to be suspended in said working bed, said 'float being mounted for rising and falling movement in said bed and meansfor controlling the pressure of air admitted to said compartment in proportion to the movements of "the float in theworking bed "to control 'the strength "of the piflsati'ons'in the water in the washing compartment, saidme'ans including a valve for regulatingthe sair dehvery of said compressor, relayimechanism for controlling "the operation of said valve, andmeansassociated with said float for operating said relay mechanism.

7 10. .A washer box for coal and the like inchidinga washing compartment, ai'closedair pressure part with said-washing compartment, bothof said com- ;partment's being adapted to be .filled with water to a common level, an air compressoL-supply pipe from said compressor to said air compartment, :means for admitting air under pressure intermittently to said air compartment above the :level oithe water therein to depress said level, said air being released between such admissions to-produce a pulsating current of water in said washing compartment, a perforated base plating in said washing compartment, the material to be washed being adapted to form a working bed on said plating, a float adapted to be suspended in said working bed, said float being mounted for rising and falling movement in said bed, and means for controlling the pressure of air admitted to said compartment in proportion to the movements of the float in the working bed to control the strength of the pulsations in the water in the washing compartment, said means including a valve for regulating the air delivery of said com-- pressor, relay mechanism for controlling the operation of said valve, control valves for operat .ing said relay mechanism,and means associated with said float for operating said relay mechanism.

a 11. A washer box for coal and the like including a washing compartment, a closed air pressure compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with water to a common level, an air compressor, supply pipes from said compressor to said air compartment, means for admitting air under pressure intermittently to said air compartment above the level of the water therein to depress said level, said air being released between such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating in saidwashing compartment, the material to be washed being adapted to form a working bed on said plating, a float adapted to be suspended in said working bed, said float being mounted for rising and falling movement in said bed, and means for controlling the pressure of air admitted to said compartment in proportion to the movements of the float in the working bed to control the strength of the pulsations in the water in the washing compartment, said means including a valve for regulating the air delivery of said compressor, relay mechanism for controlling the operation of said valve, .control valves for operating said relay mechanism, and cam mechanism for operating said control valves, said cam mechanism being operatively connected to said float for operation in relation to the movements of the float in the working bed.

12. A washer box for coal and the like including a washing compartment, a closed air pressure compartment communicating at its lower part with said washing compartment, both of said compartments being adapted to be filled with water to a common level, means for admitting air under pressure intermittently to said air compartment above the level of the water therein to depress said level, said air being released between such admissions to produce a pulsating current of water in said washing compartment, a perforated base plating in said washing compartment, the material to be washed being adapted to form a working bed on said plating, a float adapted to be suspended in said working bed, said float being mounted for rising and falling movement in said bed, air admission means for controlling the pressure of air admitted to said compartment, relay 'mechanism for controlling the operation of said air admission means and means associated-with said float for operating said relay mechanism .in proportion to the movements of the float in the working bed.

ARTHUR ALGERNONHIRST. 

